The SEI formation current density \(j_\text{SEI}\)  results from the diffusion of localized electrons, e.g. as lithium interstitial atoms \({Li^0}={Li^+}+{e^-}\) , from the electrode to the electrolyte [1]}, [2]}, [3]}. We describe this process with the long-term limit of our model developed in ref. VonKolzenberg2020,
\(j_\text{SEI}=-\frac{c_{\text{e}^\text{-},0}D_{\text{e}^\text{-}}F}{L_\text{SEI}}e^{-\frac{F\eta _\text{SEI}}{RT}}.\) 
